Systems Development...Apply project management principles to information systems projects Understand the user’s role in the development and implementation of information systems

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Copyright V.C. Storey, M.M. Moore, C. Stucke , D. Truex, 2007 1

Systems DevelopmentMBA 8125 – Week 8

2Copyright V.C. Storey, M.M. Moore, C. Stucke , D. Truex, 2007

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CorporateStrategy

ISStrategyand Plan

InternalSystems

Development

OutsourcedSystems

Development

Implementation

InternalSystems

Operations

OutsourcedSystems

Operations

Infrastructure

Security

Course Overview

OrganizationalDesign

Strategy


Learning Objectives

Describe the systems development life cycle Apply project management principles to information

systems projects Understand the user’s role in the development and

implementation of information systems Identify generic system conversion strategies Examine challenges to structured stable-state thinking Understand that security starts with development

efforts.

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Challenges & Questions

Can building new systems produce organizationalchange? Should it?

How can a company can information systems thatfit its business plan?

What are the core activities in the systemsdevelopment process?

What are the alternative methods for buildinginformation systems?


Agenda

Software Engineering Systems Development Life Cycle Alternative Methodologies

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“The study of methods for producing high quality software atminimum cost.”

Stakeholders: Users, managers, designers, programmers,competitors.

Issues: Efficiency, quality, delivery target, changingrequirements, innovation, team interaction, team incentives,project organization and management, software structure,reusability, prototyping, formal description techniques,development tools.

What is Software Engineering


Why Develop an Information System?

Phenomena that trigger IS development An opportunity (proactive) A problem (reactive) A directive

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Ultimate Management Challenge

“... It’s hard work to make improvementswithout changing anything...”

Mikahail Gorbachev, from his address to theSupreme Soviet Congress, February, 1986


System Interdependence

BusinessStrategy

Rules

Processes

Figure 1.2 (Laudon & Laudon 2006)

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Definition of Success

“A successful software project is one whosedeliverables satisfy and possibly exceed thestakeholders’ expectations, that is developed in atimely and economical fashion, and is resilient tochange and adaptation.”(adapted from Grady Booch and others) On time Within budget Meet expectations Adaptable (Why is this important?)


Agenda

Software Engineering Systems Development Life Cycle Alternative Methodologies Managing Software Projects Security

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Systems Development Life Cycle

Planning/ definition

Study/analysis

Design

Programming

Installation

Maintenance

STAGES

Project proposal reportSystem proposal report

Design specificationsProgram code

Testing and installation

Postimplementation audit

END PRODUCTS

OPERATIONSMilestone 1

Project initiation

Milestone 2Designsolutiondecision

Milestone 3 Designspecification sign-off

Milestone 4 Productiondecision

Year 1Year 2 3-8 year lifespan


Spiral (Iterative) Model

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Initial Project RisksInitial Project Scope

Revise OverallProject Plan• Cost• Schedule• Scope/Content

Plan Iteration N• Cost• Schedule

Assess Iteration N

Risks EliminatedRevise Project Risks• Reprioritize

Develop Iteration N• Collect cost andquality metrics

Define scenariosto address highestrisks

Iteration N

Iterations Retire Risks


“Make sure thesystem works!”

Importance of Testing

Unit Test Integration Test Full System Test Stress Testing Field Testing Regression Testing

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Strategies usedto convert fromone IS to another

Installation: Conversion Strategies


Activities in Systems Support

Maintenance and Support

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Agenda

Software Engineering Systems Development Life Cycle Alternative Methodologies Managing Software Projects Security


Alternative Methodologies

Other options for software development: Rapid Prototyping Iterative Development Object-Oriented Development “Off the Shelf” Applications End User Development Outsourcing

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Build experimental system to demonstrate, evaluateapproach; users refine needs

Prototype: Preliminary working version of informationsystem for demonstration, evaluation purposes

Problems: Omission of basic requirements.

Lack of documentation, testing.

Prototyping tools may not be capable of developing complexsystems.

Users see prototype and expect to be able to use it.

Alternative Methodologies:Rapid Prototyping


Prototyping Guidelines

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In iterative development, refinement of the system continues until usersare satisfied.

Alternative Methodologies:Iterative Development


• Object• basic unit of systems analysis and design• important entities (“things”)

• (e.g. customer, account, product, sale,invoice, employee, etc.)

• combine data and processes used on the data(e.g. sale may have a process or method calledcalculate_total and account may haveupdate_balance as a method)

Object-Oriented Development

Source: Laudon & Laudon 2006

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Class and Inheritance

Figure 14-9Source: Laudon & Laudon 2006

Class Name

Attributes (data)

Methods (processes)

SubClass Name

More attributes

More methods

See http://www.agilemodeling.com/style/classDiagram.htm


• Industry standard for representing variousviews of an object-oriented system using aseries of graphical diagrams

• Diagrams

Unified Modeling Language (UML)

1. Structural diagrams: relationship betweenclasses

2. Behavioral diagrams: interactions inobject-oriented system


See http://www.agilemodeling.com/essays/umlDiagrams.htm

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A UML Use Case Diagram

Figure 14-10Source: Laudon & Laudon 2006

See http://www.agilemodeling.com/style/useCaseDiagram.htm


Alternative Methodologies:End-User Development

End-users develop system with little help from technicalspecialists Small, desktop applications Users have autonomy over system

Management Benefits Improved requirements Development controlled by users Reduced application backlog

Management Problems Insufficient review / analysis Lack of standards and controls Proliferation of “private” information systems and data

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Alternative Methodology:Acquiring Software Packages

Commercial Off theShelf (COTS)Packages Set of prewritten

application softwareprograms commerciallyavailable

Modification ofsoftware package tomeet organization’sneeds

Figure 14.12 – Laudon & Laudon 2006


Purchase of an externally produced good orservice that was previously produced internally

Alternative Methodology:Outsourcing

AdvantagesEconomyPredictabilityFrees up human resources

DisadvantagesLoss of controlVulnerability of strategic informationDependency

Is Outsourcing Fool’s Gold? (Kroenke, 2006)

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Comparison of Systems Development Approaches

Can lead to proliferation ofuncontrolled informationsystemsSystems do not always meetquality assurance standards

Users control systems-buildingSaves development timeand costReduces applicationbacklog

Systems created by endusers using fourth-generation softwaretoolsRapid and informalMinimal role of IT dept

End-user Development

Inappropriate for large, complexsystemsCan gloss over steps in analysis,documentation, and testing

Rapid and inexpensiveUseful whenrequirements areuncertain or when end-user interface isimportantPromotes userparticipation

Requirements specifieddynamically withexperimental system

Rapid, informal, anditerative process

User interacts withprototype

Prototyping

Slow and expensiveDiscourages changesMassive paperwork to manage

Necessary for largecomplex systemsand projects

Sequential step-by-stepprocess

Written specificationand approvals

Limited role of users

Systems Lifecycle(Waterfall)

Approach Features Advantages Disadvantages


May not meetorganization’s uniquerequirementsMay not perform manybusiness function wellExtensive customizationraises development costs

Design, programming,installation, and maintenancework reducedCan save time and cost whendeveloping commonbusiness applicationsReduces need for internalinformation systemsresources

Commercial softwareeliminates need forinternally developedsoftware programs

Application Software Package

Loss of control over theinformation systemsfunctionDependence on thetechnical direction andprosperity of externalvendors

Can reduce or control costsCan produce systems wheninternal resources notavailable or technicallydeficient

Systems built andsometimes operated byexternal vendors

Outsourcing

Comparison of Systems Development Approaches

Approach Features Advantages Disadvantages

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• Changing demands in application development indigital firm era.

• Agility and scalability critical goals and successfactors. Strategic agility (innovation) organization mustdesign itself to be appropriately agile in response toexternal and internal forces (Gardner, 2004)

• Interorganizational system requirements whennetworks of applications are managed by differentbusiness partners

Evolving Challenges and SolutionsManagement Challenges



Evolving Challenges and SolutionsEvolving Solutions

• Building systems by assembling and integrating existingsoftware components

Component-Based Development:

• Web services –tools to build new applications or enhancingexisting systems.

• Web services -- software components deliverable overInternet; provide functions for organization’s existing systemsor create new systems that link organization’s systems tothose of other organizations.

Web Services and Service-Oriented Computing:


See http://en.wikipedia.org/wiki/Service-oriented_architecture

See http://en.wikipedia.org/wiki/Web_service

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Copyright V.C. Storey, M.M. Moore, C. Stucke , D. Truex, 2007 35

Duane Truex,

Richard Baskerville, & Heinz Klein


Revoking Traditional ISD Goals

Lengthy analysis & design are poorinvestments

User satisfaction is improbable Abstract requirements are largely imaginary Complete and unambiguous specifications are

ineffectual New systems development projects denote

failure

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Emergent Goals

Always analysis Dynamic requirement negotiations Incomplete and usefully ambiguous

specifications Continuous redevelopment Adaptability orientation


Figure . Alternative lifespan economies.(from Truex et al, 1999, CACM

Traditional

view

Emergent &

Deferred

view

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Supported by…

Back channel communications Emergent IT organizations Proper awards systems


EmergentISD: Goals

andTechniques

(from Truex et al,CACM, 1999)

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Architectural Evolution

Standalonesystems

AdaptivePatchwork

DataWarehousing

TechnicalConnectivity

EnterpriseIntegration

ComponentArchitecture

Technologicalintegration

Dataintegration

Processintegration

Source: Dr. Stefano GrazioliUniversity of VirginiaUsed with permission


Conclusions

Software engineering is challenging process Non-IS managers have important role in

software development Multiple methodologies for developing

software Information systems differ No development process works in all situations

Difficult to manage software projects

Documents

Systems Development...Apply project management principles to information systems projects Understand the user’s role in the development and implementation of information systems